Strategies for Internet citizens

A conversation with Bill Crow about HD Photo

For the last five years, Bill Crow has been working on HD Photo, a new image file format that’s intended to supplant the JPEG format currently at the heart of the digital photography ecosystem.

I first met Bill many years ago when he came to BYTE to show us HP NewWave, which was probably the earliest effort to produce an object-oriented file system for Windows — originally, believe it or not, for Windows 1.0. The connection between NewWave and HD Photo is tenuous, but it does exist in the sense that the metadata strategies we’re seeing today (see the truth is in the file) point the way toward ending the tyranny of the hierarchical file system.

Today’s podcast begins by revisiting NewWave, but it’s mostly about HD Photo: Why it was created, how it works, what it will mean to both amateur photographers (“happy snappers”) as well as pros, and how it will be standardized and baked into a next generation of digital cameras.

Along the way I learned a huge amount about the current state of digital photography. For example, I knew that pros prefer to shoot in RAW format, but I wasn’t clear what that meant. According to Bill, a RAW image is just sensor data from a high-end camera, which photo processing software later turns into an image. The professional photographer trades away convenience for control and flexibility. In the case of the JPEG images produced by the vast majority of digicams, though, it’s the other way around. We get usable images without any fuss, but we give up the ability to reinterpret the data. HD Photo aims for the best of both worlds: ultimate control and flexibility if you desire, convenience when you don’t.

Although Bill guesses we’re two years away from commercial HD Photo cameras, the format is being used today to support Photosynth. As he explains on his blog, a compressed Photo HD image has a regular structure that makes it possible to extract images at various levels of detail without decoding the entire image.

There’s a whole lot more to the story. I hugely enjoyed this conversation, and I think you will too.

JPEG-2000 offers very good compression efficiency, but this comes at the expense of computational complexity. The JPEG-2000 encoder and decoder require a lot of CPU horsepower and memory. That’s one of the reasons that despite the fact it’s been around for a while, there are no cameras that currently support JPEG-2000. It’s simply too complex for low-cost or low-power embedded implemenations.

We’re very pleased that HD Photo delivers compression efficiency equivalent to JPEG-2000, but with an extremely efficient, device-friendly algorithm that is perfectly suited for implementation in cameras and other low-cost consumer products. Additionally, HD Photo offers a much greater range of pixel formats as well as some additional features and capabilities not provided by JPEG-2000.

All of use who are interested in alternatives to JPEG are not much impressed by HD Photo’s computational efficiency. It’s nice, yes, but by the time it hits the camera market they’ll be fast enough to mange JPEG 2000.

No, what we want to know is intellectual property rules. We can’t use JPEG 2000 because it’s widely assumed that there are potential patent fights on the math. What will Microsoft do to make HD Photo a standard? Will they completely surrender control? Will they foreswear any side patent agreements? Will they commit to fighting the inevitable challenges?